1. Field of the Invention
The present invention relates to an apparatus for fabricating a sintered oilless bearing and method thereof, and more particularly to an apparatus for fabricating a sintered oilless bearing, wherein the sintered oilless bearing is corrected by means of a correcting rod shaped to be identical to projections and grooves formed along the inner periphery of the sintered oilless bearing for exactly match the concentricities of the projections and grooves to make a kinetic pressure generating force consistent and improve a bearing force.
2. Description of the Prior Art
A general sintered oilless bearing has disclosed in Japanese Laid-Open Patent No. hei 5-180229, which, as shown in FIG. 1, is formed such that sintered oilless bearing 1 is molded by forming a plurality of projections 2 and grooves 3 along the inner periphery thereof. Then, it is subjected to the sintering treatment to have porosity capable of absorbing oil. Under the sintered state, the oil is impregnated to push-fit bearing 1 into a housing which forms a motor. Also, once a correcting rod 4 is forcibly inserted into the inner periphery of bearing 1 during the push fit process to correct projections 2 to have a desired inner diameter, porous oil absorbing holes finely-formed in the inner surface of respective projections are clogged while the oil absorbing holes of grooves 3 are unblocked.
Upon inserting a shaft into the inner periphery of sintered oilless bearing 1 provided as above, the outer periphery of the shaft becomes in contact with respective projections 2. Thus, while the shaft is rotated at high speed, the oil is supplied into the oil absorbing holes of respective grooves 3 to generate the kinetic pressure between projections 2 and rotatably support the shaft.
The conventional sintered oilless bearing 1, however, involves contraction during the sintering process to differ the concentricities of projections 2 and grooves 3. That is, when performing the sintering, there is no separate architecture for gripping the positions of them to differ the concentricities of respective projections 2 and grooves 3 with the consequence of varying pressure distribution throughout respective grooves 3 to make the generation of the kinetic pressure inconsistent.